


Day One: Modern AU

by Moonblastbitch



Series: Dimileth Week [1]
Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe, Alternate Universe - Modern Setting, Cat Burglars, Cowgirl Position, Cunnilingus, Dimitri is feral, F/M, Private Investigators, Smut, byleth is wearing leather, you know whats goin down
Language: English
Status: Completed
Published: 2019-09-22
Updated: 2019-09-22
Packaged: 2020-10-21 19:36:24
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,641
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20698769
Author URL: https://archiveofourown.org/users/Moonblastbitch/pseuds/Moonblastbitch
Summary: Day One of Dimileth Week.Disillusioned PI Dimitri Alexandre Blaiddyd is hired to protect the precious jewels of a famous opera singer from a rash of burglaries. While on the job he comes face to face with an old flame.





	Day One: Modern AU

**Author's Note:**

> DAY ONE HERE WE GO!!!!! 
> 
> For those who don't know, September 22nd-28th is Dimileth week! In honor of this amazing fanbase I wrote seven fics that will be released once a day. The first of which is a modern cat burgler/PI romance I promised to my dear friend Hatta ages ago! 
> 
> I've been working on this guy off and on for the better half of a month, so please enjoy this little labor of love! 
> 
> Big Big Big thanks to my darling friend and fellow Dimitri thirster Rie who actually read through not only this fic but all of them for this month. She really helped me with grammar and pacing and I cannot thank her enough.

Dimitri no longer slept at night. Night was full of terror, full with the ghosts of what could have been. He found no comfort in rest, it only made him feel more susceptible to attack. As a result, he did his best work at night. Luckily for him it suited his career choice well. 

Tonights mission was a bit different than the usual “hunt down my shitty ex” jobs. Some opera diva expat from the Empire was in need of protection. Not for her, but for some precious stones. She came in with a laundry list of demands, hotly arguing with his secretary Ashe as he tried to find some middle ground for her. 

“My friends are being attacked! Disarmed! Violated in their own homes! Just last week my darling friend was robbed blind! I’m next I know I am!”

“I understand ma’am but we can’t spare the manpower. We only have six people on staff, including myself, two of them are on vacation and the other two are already on another case.” Ashe reasoned, to no avail.

“Why would you let not one but two people to leave at such a critical time?! Who allowed this?!” She demanded.

“I did.” Dimitri said, stepping out of his office. The woman snapped her jaw shut. Apparently she was a bit intimidated by him. Most were. He had the look of a feral junkyard dog. According to Felix he also acted like it.

“Helllooo handsome. So you’re the boss around here?” She flirted, coyly twisting a lock of hair around her finger.

… Or maybe not. 

“What's the issue?” Dimitri grunted at Ashe.

The secretary gave a long sigh. “She needs someone to watch her jewelry 24/7 while she's out of the country.”

“Excuse me? My jewelry? No no no, this is not some simple costume jewelry! This was a gift from the Emperor himself when he saw my historic performance of ‘Soothis in Flight’! It brought him to his knees! He had them custom made and I became a guest of his court!”

“Twenty years ago.” Ashe muttered.

“What was that?” She asked dangerously.

“You can't just get a damn security system?” Dimitri asked, already exhausted at the idea of taking this case.

“Ha! A security system did not help Dorothea! I want the very best, and I’ve been told that this is the very best! So can you help me or not?”

He and Ashe gave each other a sidelong glance. Was the money really worth the cost of dealing with her?

“I’ll make it worth your while.” She said nervously to the two.

Dimitri raised one eyebrow, intrigued. 

“I’ve been told you’re looking for someone.” She said, feigning a casual tone. “Edelgard von Hresvelg right? I have a friend whose in close relation to her. I bet I could get you an audience.”

Ashe looked up at him, a worried expression marring his face. Dimitri could feel the rage build up inside him. One pseudo guard job and then finally after all these years he could force that woman to answer for her crimes. It was no longer a question of if, but when.

“I’ll take it.”

“I really don't think that's a good id-”

“Get her paperwork ready.” He barked, heading back into his office. He could hear Ashe sigh behind him. Dimitri slammed his door, not wanting to hear anymore of his well meaning arguments.

Ashe, like the rest of his staff, were playing a losing game. Trying to save his immortal soul. They should have known hope for that left long ago.

Left with her.

Two hours later, Dimitri was in the richest part of town. The sparkling mansions on the hill he once felt comfortable in now reminded him of tombs. Manuela was tugging on his arm, schlepping him across her grand marble floors, giving him a full tour of the house. He couldn't fathom why. He was only going to be in her ‘gallery’. What a waste of good space.

“So do you have any questions? Any demands? I’m happy to give you whatever you might… desire.” She said with a wink. Dimitri rolled his eye. This woman was impossible.

“Just stay out of my way. I’ll babysit the damned jewels.”

“Oh my, a bit prickly are we? No matter, I’m sure I’ll break through that rough exterior eventually.”

“You won’t.”

Manuela huffed childishly, then led him to the gallery. He was supposed to guard a room like this? It was a logistical nightmare! Wide, open windows left observation from potential thieves simple, and the pride that she displayed the necklace was not reflected in the construction of its case. Any child with a lockpick could come in here and snatch it.

“Remove the necklace.” He told her, intending to place a fake as bait for the burglar.

“I will not! Do you have any idea how delicate it is? The last time I wore it in public I nearly snapped the chain in two! Oh it broke my heart to have it repaired. Ever since then its been as fragile as glass.”

Dimitri eyed the jewelry. It certainly looked well constructed. How on earth had she managed to break the damn thing?

“My- ahem- gentleman caller for the evening got a might bit…. Over zellous. Oh I was so angry I chased him out of my boudoir, throwing my shoes at him. Oh memories.” Maneula sighed fondly.

Ah.

“I’m securing the room. Leave.”

Manuelas face lit up with anger. “How dare you! This is my house. Listen up Cyclops I will not be bullied by some big headed bas-”

“Get. Out.” 

“Fine! But don't expect a bonus in your paycheck!” She said, storming off. Dimitri waited until her car pulled out from the parking lot. Then he got to work.

Private home heists of this prestige usually took months to plan. He was already working against the clock if the burglar had already managed to canvas the home. The rich could be suprisingly trusting. All someone needed to do was show up in a workmans uniform and one could easily plant bugs in the home and the owners were none the wiser.

Dimitri carefully searched every nook and cranny of the room. No such luck. Either the thief had taken the bug out already or he’d never even left one. Winging it was not uncommon amongst the criminal element and most people were woefully unprepared for an emergency. Even the one percent.

As the day wore on and the soft pink of the sunset unfolded across the gallery he couldn't help but be more annoyed with himself. What was the actual chance of a thief showing up today? This felt like a waste of time on the guess of some washed out singer. He should be out trying to track that woman down, wherever she might be hiding. 

He rubbed his temples. He’d forgotten to eat today, and he couldn't recall drinking anything either. Dedue usually made sure he was keeping up on those routine maintenses but he’d been out on a case for the past three days with Felix. He now felt the weight of his inaction as his head pounded and stomach growled.

This infernal body. It forced him to rest, eat, all things that got in the way of his mission. He roughly pounded on his chest, willing the feeling to go away. When it became apparent that it wouldn't he stalked downstairs. The house was a damned labyrinth, finding anything inside was nye impossible without a roadmap. 

Eventually he made is way downstairs to a kitchen that looked as if it had been crystallized. Everything was clear like glass, from the sink to the fridge to the countertops. Dimitri rolled his eyes at the excessive display of wealth and dug around until he found an apple. That would stave off his hunger for now. 

He took a minute to examine the house further. A breakin was possible from any angle. Did this woman not believe in locks or something? At least the house came with vaulted ceilings, the echoes of anyone coming in or out would be an aid, should anything actually happen tonight.

He took a bite and walked around the hallway. Each door was a tiny alarm, though he could tell by the model that it was the outdated kind that just rang and it was up to the owner of the house or the neighbors to alert the police. He scoffed. No wonder she felt the need to hire personal security.

Eventually he made his way back up to the room, still just as it had been. The sun was dipping lower in the sky, highlighting the entire neighborhood with rich purple hues. He felt a twinge of nostalgia as he remembered a certain night from his academy days. He quickly shoved the feeling aside. No need for that here. 

He sat back against the window and waited. Considering the limited information he had there was no way to predict a break in. Ashe had been kind enough to produce a file on the four burglaries Manuela was sure were perpetrated by the same person. He read through the section about her friend Dorothea, where the singer had testified about the incident.

“I was coming home from a long night out with friends when I noticed one of my windows was ajar. I called the police on my cell and rushed up to my study where the open window was. Inside everything was a mess and the safe where I kept my valuables was open. I got one quick glimpse of the thief. I couldn't tell if it was a man or a woman but they had a dark suit on and looked to be about 5’6. They saw me and jumped out the window, and by the time the police arrived they were gone.”

According to his assistant the description was in line with what every person saw at the scene. Room destroyed, valuables gone, and if they saw the thief it wasn't for very long. Dimitri rubbed his chin in contemplation. The police reports mentioned that no DNA had been taken from the scene, and the only camera that managed to catch the mystery person was grainy at best. This was clearly the work of a pro. Meaning the chances of catching them were slim to none.

Dimitri sighed and threw the report to the side. This trap felt woefully underwhelming, and he felt next to useless. Even if he caught this mystery thief what were the chances that Manuelas friend could actually get him a meeting with Edl- her. The chief of police was rarely seen in public nowadays. For good reason too. She knew he was after her.

He tightened his fist. He was getting close. He had proof of her corruption. Proof of her involvement with the Duscar incident. He just needed a little more. Some testimony, a confession, anything! But everyone was too afraid what would happen if they disobeyed her. 

Everyone except him.

Lost in thought, he looked up and saw the room had grown dark. It seemed that he had nodded off for a moment. He stood up and checked the room, then sighed. Everything was still in order. Of course it was. What burgler would want some stupid necklace?

He moved to the front of the case and studied the piece. Despite his original misgivings it was rather stunning. It was covered in rubies, with pearls encrusted on the border to give the piece a more sharp look. It would go for a pretty penny on the black market.

As he gazed at the treasure he’d been hired to protect he heard a noise. Just a small creek at the doorway. He straightened his posture, then turned to the door slowly.

The door was open slightly, most likely brushed by a draft. He tilted his head in observation, then flinged the door open fully. He imagined a cat burglar, dressed like an old cartoon character, frozen at the door with a sack full of oversized diamonds. Unsurprisingly, there was no one outside. He rolled his eye and shut the door.

Right then a leg swung at him. Stunned, he stepped back, dodging the mystery assailant as they flung punch after punch at him. No way. Was this the thief? Here? Now?

Dimitri shook himself out of his stupor and considered his surroundings. The gallery was a large room, with plenty of space. He could lead the burglar away from the jewels, knock them out on the open carpeted area, then call the police.

The cat thief must have seen the gears of his mind turning and she swiftly kicked him in the head. They were powerful he’d give them that. Blood gushed from his nose and the pain made him wince. It was likely broken. Again.

Rather than tend to the injury he pushed the thief back, grabbing the leg that kicked him and shoved their body down. Before they could respond Dimitri lept on top of them, shoving his body against theirs, folding their arms into a vice above them.

“You’re caught. Stand down and I won't hurt you.” He said calmly.

The thief gasped under their mask. The chaos of the fight left them unable to see each other. But now on the ground with the soft glow of the street lights both of them could get a glimpse of each other.

He realized it was a woman he was holding. Covered head to toe in a tight black catsuit it was a wonder they weren't able to identify her as such in the first place. Dorothea was correct in her original description. She was only about 5’6. But the uniform of her profession did very little to hide her gender.

She was curvy, thickly built with wide hips, large breasts and a short frame. Once upon a time she would have been his exact type. His eyes lingered at her neck, where the mask met the suit and a strip of pale skin was revealed. The woman moved her legs restlessly, trying to find a foothold to flip the two of them. But he was one step ahead, pressing down on her thighs with his knees.

“Give. It. Up.” He growled, barely containing his rage. 

She said something, muffled underneath her mask. He moved his free hand to her neck, inching the article up. She shook furiously under him and he ripped it off in one fell swoop. The woman beneath was beautiful. Familiar. A spark of recognition struck him and he realized exactly who he’d just taken to the floor.

“You?!?!” He gasped out, clutching the mask for dear life.

She said nothing, opting instead to take advantage of his shock and swap their positions, leaving him to her mercy.

“What are you doing here?” She grunted out, caging his legs under her powerful thighs.

“What are you doing stealing jewelry?” He grunted bellow her. Besides the catsuit, she was just as he remembered. 

“Its personal. What are you doing guarding jewels?” She asked. He could feel her tremble on top of him. As unemotional as she tended to be clearly his presence affected her.

“Personal.” He snarked at her, before wrapping her arm with his and slamming her to the floor. He had her pressed tight against him, no room for either of them to move. He’d learned not to underestimate her.

She grunted under him, wriggling around trying to find some way to get the upper hand. He bit his tongue as she brushed against his groin. Now was not the time for that.

She glanced up at him, noticing his reaction. “It's been a long time.” She said, concentrating her movements onto his crotch.

She always did know how to take advantage of his weakness for her. He ground down into her, earning a sharp gasp. Two could play at that game.

“Why come back? After all this time?” He asked her, lacing his hands into hers. He reasoned to himself that this was purely strategic, a way to disarm her. But as he felt her small fingers interlock with his he couldn't help but think back to easier days.

She saw his hesitation. She forced his hands down until his back was on the floor. Before he could get up she sat on his chest.

“I have a job to do.” She grunted, forcing his hands above his head. He rolled his eye.

“A job? Exactly what kind of job entails breaking into random opera singers houses?”

She glared at him. Apparently she wasn't going to just give that information away. He lifted his hips up, causing her to slide down from his chest to his neck. Her face was as stoic as always but he could see a glimmer of lust floating just underneath.

“What are you doing?” She asked, ignoring his questions.

“Just getting comfortable.” He said snidely. He could smell the leather and sweat all over her. Her thighs tightened around his throat in a clear warning. He considered his options. He could either wait for her to give him an opening (risking her snapping his neck in the process) or he could throw her off of him and grab for his cuffs, to which she’d have ample time to escape. Both seemed unlikely to result in victory.

Unless he did something surprising that is. 

Byleth watched him closely, waiting for his next move. Neither of them knew what to do. How does one deal with their ex becoming a cat burglar? Or a PI for that matter. He decided it was only fair of him to break the tension.

He ducked his head sliding right underneath her. He could feel her legs compact around him in an attempt to stop him, but it was no use. He burrowed his bruised nose into her leather covered groin causing the woman above him to gasp.

He felt dark sadisfaction deep in his belly. He knew that noise very well. He used to love hearing it when they hopelessly grinded against each other in their small bunks at the police academy. But that was a long time ago. He stuck his tongue out and rubbed the seam of her suit, his pace punishing.

Byleths grip on his hands was slipping. Logically this would be the time to flip her, cuff her and be done with it. But hearing her stifled moans he couldn't bring himself to even try. Her hips were moving against his lips, small hesitant thrusts that told him she was feeling the exact same as him.

She released his hands suddenly. In response Dimitri grasped her waist, pressing her tighter against him. Above him he heard the tell-tale zipper of her catsuit. She slid away from his mouth, moving south to sit snugly on his hips. She had brought her zipper down to her stomach, her cleavage hanging tantalisingly free. Her face was flushed and her eyes were wary. He felt his rage spike. Why would she be worried? She was the danger here.

“I hate you.” He growled out.

“I know.”

They looked at each other for a beat, then Dimitri pulled the suit from her shoulders roughly. She watched as he undressed her, her expression becoming less guarded and more distracted. He pulled her roughly into his lap facing away from him. Without warning he shoved his hand into the suit that still covered her legs.

Byleth jumped from his action, pressing her back tightly to his chest. He rubbed fiercely at her soaking pussy, uncaring of the groans she bit back. He was on a mission. He wanted her to remember exactly the way he always made her feel. He trapped her clit in between two fingers and pinched it.

“Ah-h! Dimitri!” She shouted, half in pain, half in pleasure. He ignored her and grinded his palm into her groin. Byleth jolted against him, throwing her head back as she moaned to the heavens. He felt her hands pat around them experimentally, searching for something. He sucked in a breath as her right hand reached between them to find his straining cock.

“Don’t.” He barked into her ear.

She ignored him, undoing the zipper on his pants. He growled again, using his free hand to pull hers away. 

“Do not. Touch me.” 

She rolled her eyes and he inserted two fingers into her. She shivered and grinding against his hand. “Why not? I’m letting you touch me.”

He rubbed her clit faster, ceasing her questions all at once. The hand he held in his grasp opened and closed around his fingers. She was close. The pressure in his stomach coiled tightly as he thought of her climax. She never was the most expressive person so every gesture and look felt like a victory back then. When they started messing around he relished seeing her face twist as she writhed against him. It was as invigorating as it was torturous.

She bounced up and down on his lap, rubbing herself against his cock. He looked down at her face, scrunched up delightfully, and smirked. Only he could make her look this. Dimitri dove for her neck as she squirmed against him, leaving a bruising bite. He felt her walls tighten around his fingers, and with one finally nudge she came.

She shook violently and he released her hand to grab her chin, forcing her to look at him. Her eyes were half lidded and her mouth was parted deliciously. He jammed his tongue inside. She jerked against him as he licked and sucked every part of her open, vulnerable mouth.

She broke the kiss and shoved him on the ground. For a moment he thought she’d make her escape. But before he could react she climbed back on top of him, unbuttoning his shirt. He obliged her, shifting so she could pull the offending article off of him. 

“Oh so I’m allowed to touch you now.” She remarked with no humor in her voice.

“Shut up.”

She raised one eyebrow but continued in her quest to disrobe him. Impatiently she tugged his pants off, freeing his cock in one move. Dimitri hissed as the air hit his throbbing length. Byleth took it into her hand, running her thumb lightly over the head. He gritted his teeth, watching as she gazed down at him.

“Some things never change do they Beloved?”

He glared at her. She had no right to call him that anymore. He had half a mind to stop this nonsense right now. Capture her, take her to the police, and let her deal with the justice system.

That was, until she took him inside of her.

He gasped, his back arching as she lowered herself steadily onto him. Her thighs clamped around him, creating a vice he wouldn't dream of escaping from. She smiled and moved her hips in tight circles, groaning when he was fully inside her.

Byleth pressed her hands against his chest, balancing herself delicately as she rode him to kingdom come. He wanted nothing more than to lay back and close his eyes while she did all the heavy lifting. But he didn't trust her. He may love her, spend his nights obsessing over her, but no way did he trust her.

She sighed above him, flinging her head back gracefully while she bounced up and down. He focused in on the column of her neck, his palms itching to reach out and grasp it. He settled for her hips instead, jamming her down onto his cock.

The added pressure was causing white spots to form in his vision. It was so much at once. Byleth must have noticed as she deviously increased her pace. Payback for earlier, he thought. She still adored being his undoing, that much had not changed.

She was sweating above him, he noticed. Little dots forming around her chest, her forehead. She was exerting a lot to please him. The thought made shivers race across his spine. She hunched over him, just an inch or two from his lips.

He reached a hand up and grasped a fist full of hair. It was a sea green color now, matching her eyes. He hadn't noticed it in their earlier struggle but it looked good. He pulled her down to meet his lips, kissing her fiercely.

She moaned into the kiss, reaching one hand down to finger her abused clit. He was almost tempted to pull it away. She already got hers, why does she need another? But he decided that would be too cruel. He reached down to meet her hand, pressing down. She replaced her hand with his own and grinded into his palm, panting with every rub.

“Dimitri…. I.”

He kissed her before she could say anymore. He was nearly at his limit too. Her addictive little bounces made his stomach coil and with one last agonizing thrust into her he came. Byleth shuddered, falling against his body as she milked the last of him. 

His hand was trapped between the two of them as he rubbed her clit. She pressed her mouth into his neck, muffling her sweet moans. It wasn't much longer before she joined him, shaking and then finally falling into a heap next to him.

They laid together for a minute in complete silence. Dimitri looked around the room. Their little scuffle had resulted in half the room being torn apart. The gauzy curtains that Manuela had hung in every aperture were destroyed, the sitting area was tossed and the bay window was still wide open.

“Is this how you treat all thieves?” Byleth asked from beside him. He glanced over to her. She looked like a dream. Her hair was mussed, her catsuit was still clinging to her calves and her whole body had the distinct glow of sweat.

“You’re a special case.” He grunted.

“Really? How nice.” She said, standing up.

Dimitri jumped up next to her, still cautious of her next move. She looked over her shoulder at him. “Relax. You won today.” 

He didn't believe that for a minute. There, stark naked in the moonlight Dimitri circled her like a shark as she languidly dressed herself. Though she didn't show it on her face she had a self satisfied aura about her that both titillated and pissed him off.

“I’m arresting you.” He said finally as she zipped herself up to her chin.

“Isn't that a compromise of morals? Fucking then arresting?” She asked.

“Shut it.” He barked, grabbing her wrist.

She slid out of his grasp easily and with one swift kick to his shins had him on the ground. She sat back on top of him before he could react.

“I’m going to leave. You’re staying here.” She whispered in his ear dangerously. He tried to grab at her but she was too quick, hoping up from his chest and bounding to the window. 

“You cannot run from me forever.” He groaned, still in pain on the floor.

“I know. Just for now.” She responded. Without another word she slipped out of the window. Dimitri got up and looked around furiously. He couldn't chase after her in the nude (though he had a feeling she might enjoy him trying). He hit the wall angrily. He was this close. But he let her distract him.

Again.

Alarm bells rang distantly in his head. He rushed over to the jewel case. Luckily the necklace was still inside. With an added note. Hurriedly he opened up the case, picking up the note left inside.

234-594-9911

He groaned. What kind of cat burglar leaves a phone number? He grabbed the paper, moving to stuff it in his pocket. Until he remembered he wasn't clothed.

“God damnit.”

**Author's Note:**

> Okay everyone what did we think? This was actually my first time writing a modern au so I hope I did the prompt justice! 
> 
> Most of the story is pretty implied so it can be kind of all over the place as a result. Just know that Dimitri and Byleth used to be cops together, with her being his mentor, and then shit fell apart. I'm considering turning this into a whole series. If that sounds interesting to you please let me know.
> 
> And before you click out please leave me a comment and kudo! It means the world to me.
> 
> P.S. Can you tell I have a thing for Byleth in catsuits?


End file.
